Microbial ecology and intraspecies diversity of a traditional algerian sourdough: a unique consortium of lactic acid bacteria and Pichia strains from mawna wheat fermentation

Abstract

ABSTRACT Traditional sourdoughs harbor unique microbial ecosystems, are essential for the organoleptic and nutritional quality of bread. This study explores for the first time the microbial ecology of a spontaneous sourdough produced from a whole wheat flour of an endemic Algerian variety (Triticum aestivum L., cv. Mawna). The physicochemical dynamics (pH, titratable acidity) and the microbial community were characterized over five days of fermentation. Hence the molecular identification (16S rRNA and ITS region sequencing) revealed a stable and original microbial consortium. While the bacterial community was composed of three dominant species: Lactiplantibacillus plantarum, Enterococcus faecium, and Leuconostoc fallax. Moreover, it is worth mentioning, the yeast community was exclusively composed of the species Pichia kudriavzevii, in which a comparative sequence analysis revealed however for the first time, a significant intraspecific diversity within this ecosystem evidenced with the presence of three distinct strains. Phylogenetic analysis confirmed the identity of these isolates (>99% similarity with reference strains). The coexistence of this trio of lactic acid bacteria with a pool of Pichia kudriavzevii strains suggests a complex symbiosis, specifically adapted to the Mawna wheat flour. These findings highlight the richness of traditional Algerian sourdoughs and identify a promising microbial consortium. Which seems to be a prime candidate for the development of indigenous starter cultures, improving thus the technological, aromatic, and preservative properties of breads made from local cereals.